Effects of sex and dietary lysine on performances and serum and meat traits in finisher pigs

Abstract

A total of 160 Duroc × (Landrace × Large White) pigs, 50% barrows and 50% gilts, of 28.3 ± 4.52 kg of BW were used to study the effect of lysine (Lys) restriction in the finisher period, on growth performances and serum and carcass and meat quality traits. The grower diet (from 30 to 90 kg BW) was slightly Lys-restricted (7.8 g standardised ileal digestible (SID) Lys/kg) in accordance with results from a previous trial. During the finisher period (90 to 130 kg BW), four experimental diets with decreasing SID Lys contents (6.3, 5.6, 4.2 and 3.2 g/kg) were tested. Each of the eight treatments (two sexes × four levels of Lys) was replicated five times. Each replicate was a pen with four pigs allocated together. When animals achieved 129 ± 2.59 kg were slaughtered and carcass and meat characteristics were evaluated. No significant interaction sex × diet was found. During the finisher period, barrows grew faster ( P < 0.001) and ate more feed ( P < 0.001) but tended to be less efficient ( P = 0.055) than gilts. The Lys restriction affected linearly ( P < 0.001) all productive performance traits; daily BW gain and feed intake decreased and feed conversion ratio increased. Also, the concentration of serum urea at slaughter tended to be higher in barrows than in gilts ( P = 0.065) and was reduced quadratically by the restriction of Lys in feed ( P < 0.001). Carcasses from barrows had higher backfat thickness ( P < 0.01) and lower weight of main trimmed lean cuts (ham + shoulder + loin; P < 0.05) than those from gilts. The Lys restriction during the finisher period decreased carcass yield (quadratic; P < 0.001) and the weight of major cuts (linear; P < 0.001). Sex and diet had limited effect on meat characteristics; the Lys restriction decreased quadratically the proportion of protein ( P < 0.01) and increased linearly the intramuscular fat (IMF) content ( P < 0.001). We can conclude that dietary Lys restriction during finisher period in pigs impaired growth performances and was not successful to increase the carcass fat deposition, although it could have positive effects on IMF proportion of pork.

Effect of advancing the supply of finisher diet on growth performances and carcass and pork quality of heavy barrows and gilts

“…Under ad libitum conditions, barrows are commonly found to consume more feed than gilts (Latorre et al, 2008;Suárez-Belloch et al, 2015a and2015b) which is confirmed by the results of this experiment, being the difference 160 g/day on average. This value is not far from the 220 g/day reported by Rodríguez-Sánchez et al (2011) and explains the faster daily gains recorded in barrows compared with gilts.…”

“…Taking into account that the aim of the trial was increasing fatness, a slight impairment of FCR could have been carried out. In fact, in the literature, worse feed efficiency has been reported as a result of dietary protein or Lys restriction in both the grower (D'Souza et al, 2003) and the finisher phase (Campbell et al, 1984;Suárez-Belloch et al, 2015b). The result of the current work is positive, under a productive point of view, but it would indicate that the nutrient restriction generated advancing the finisher diet by 21 days was very limited.…”

“…However, in the Mediterranean countries, fatter pigs are required for elaborating cured products, such as ham, due to the beneficial effects on processing and eating quality (Ruíz et al, 2002). Several nutritional strategies are being evaluated to achieve a certain level of backfat depth and also of IMF; for instance, the restriction of dietary CP (D'Souza et al, 2003) and/or Lys (Suárez-Belloch et al, 2015a and2015b) as the first-limiting amino acid for growth. The reduction of these nutrients in diet would decrease the rate of protein synthesis increasing the proportion of energy retained as fat (Adeola and Young, 1989).…”

Influence of mild feed restriction and mild reduction in dietary amino acid content on feeding behaviour of group-housed growing pigs

“…It is commonly accepted that a reduction in dietary net energy (NE) content leads to an increase in feed intake to keep the NE intake constant (Cámara et al, 2016), although the influence of nutrient deficiencies, particularly of indispensable AA, is controversial. Some authors found that voluntary feed intake decreased when pigs were placed on diets that were deficient in protein or indispensable AA (Gallo et al, 2015;Schiavon et al, 2015;Suárez-Belloch et al, 2015), especially tryptophan (Henry et al, 1992;). Other studies found that mild deficiencies in protein, lysine or threonine resulted in increased feed intake (Ferguson and Gous, 1997;Henry, 1995;Chiba et al, 2002).…”

miR‐17‐5p Regulates Differential Expression of NCOA3 in Pig Intramuscular and Subcutaneous Adipose Tissue

“…High IMF content relative to subcutaneous fat is a target of genetic selection. Studies show that intramuscular fat content is highly heritable [19] and is positively correlated (r = 0.45) with subcutaneous fat thickness [20]. However, the physiological function and lipid metabolism ability of different adipose tissues differ [21][22][23].…”